Image forming apparatus, image forming method and computer readable medium

Abstract

An image forming apparatus includes a sheet feeder, a sheet conveyor, an image former, a fixer, a colorimeter and a processor. The fixer fixes an image formed on a sheet by the image former. The colorimeter is provided on a down-stream side than the fixer in a sheet conveying direction and reads the image. The processor calibrates the colorimeter based on the image read by the colorimeter. When an image for calibration which is formed in advance on a color sample housed in the sheet feeder is made to be read by the colorimeter, the processor controls at least one of the sheet conveyor, the image former and the fixer according to a condition for controlling deterioration of the color sample which is different from a condition of when carrying out an image forming.

What is claimed is: 
     
       1. An image forming apparatus comprising,
 a sheet feeder which houses and feeds a sheet; 
 a sheet conveyor which conveys the sheet fed from the sheet feeder; 
 an image former which forms an image on the sheet; 
 a fixer which fixes the image formed on the sheet by the image former; 
 a colorimeter which is provided on a down-stream side of the fixer in a sheet conveying direction and which reads the image formed on the sheet; and 
 a processor which calibrates the colorimeter based on an image for calibration read by the colorimeter, the processor controlling at least one of the sheet conveyor, the image former and the fixer according to a condition for controlling deterioration of a color sample housed in the sheet feeder when the image for calibration, which is formed in advance on the color sample housed in the sheet feeder, is made to be read by the colorimeter, the condition being different from a condition for carrying out an image forming process; 
 wherein, when the processor makes the sheet conveyor convey the color sample, the processor makes a pair of rollers of the fixer separate from each other and makes the color sample pass through the pair of rollers; 
 wherein, the processor determines whether a sheet length of the color sample in the sheet conveyance direction is longer or equal to a predetermined sheet length, which allows the color sample to be in contact with a conveying roller in front of the fixer and a conveying roller behind the fixer; and 
 wherein, when the processor determines that the sheet length of the color sample is longer or equal to the predetermined sheet length, the processor makes the sheet conveyor convey the color sample, and wherein when the processor determines that the sheet length of the color sample is less than the predetermined sheet length, the processor displays a warning to use a sheet whose length is longer or equal to the predetermined sheet length. 
 
     
     
       2. The image forming apparatus of  claim 1 ,
 wherein, when the processor makes the sheet conveyor convey the color sample, the processor determines whether a setting temperature of the fixer is lower or equal to a predetermined temperature which is lower than a temperature of when carrying out the image forming process, and 
 wherein, when the processor determines that the setting temperature of the fixer is lower or equal to the predetermined temperature, the processor makes the color sample pass through the fixer. 
 
     
     
       3. The image forming apparatus of  claim 1 , further comprising:
 a flattener which is disposed between the fixer and the colorimeter and which corrects deformation of the sheet, 
 wherein, when the color sample is conveyed by the sheet conveyor, the processor makes the color sample pass through the flattener after turning the flattener off. 
 
     
     
       4. The image forming apparatus of  claim 1 , further comprising:
 a detour path which avoids the fixer, 
 wherein, when the color sample is conveyed by the sheet conveyor, the processor makes the color sample be conveyed on the detour path which avoids the fixer. 
 
     
     
       5. The image forming apparatus of  claim 1 , wherein, when the color sample is set as a paper type of sheets housed in a sheet feeding tray of the sheet feeder, the processor stops receiving an image forming job and only carries out a passing operation of the color sample. 
     
     
       6. The image forming apparatus of  claim 1 , wherein, when the color sample is set as a paper type of sheets housed in a sheet feeding tray of the sheet feeder, the processor controls a setting temperature of the fixer so as to be lower or equal to a predetermined temperature which is lower than a temperature of when carrying out the image forming process. 
     
     
       7. The image forming apparatus of  claim 1 , wherein, when the color sample is conveyed by the sheet conveyor, the processor makes the color sample be conveyed at a speed faster than or equal to a fastest conveying speed available in the image forming process. 
     
     
       8. The image forming apparatus of  claim 1 , wherein the processor automatically cancels a setting that a paper type of sheets housed in a sheet feeding tray of the sheet feeder is the color sample after the colorimeter is calibrated based on the image for calibration which is read by the colorimeter. 
     
     
       9. An image forming apparatus comprising:
 a sheet feeder which houses and feeds a sheet; 
 a sheet conveyor which conveys the sheet fed from the sheet feeder; 
 an image former which forms an image on the sheet; 
 a fixer which fixes the image formed on the sheet by the image former; 
 a colorimeter which is provided on a down-stream side of the fixer in a sheet conveying direction and which reads the image formed on the sheet; and 
 a processor which calibrates the colorimeter based on an image for calibration read by the colorimeter, the processor controlling at least one of the sheet conveyor, the image former and the fixer according to a condition for controlling deterioration of a color sample housed in the sheet feeder when the image for calibration, which is formed in advance on the color sample housed in the sheet feeder, is made to be read by the colorimeter, the condition being different from a condition for carrying out an image forming process; 
 a PI tray for insert sheets, which is provided in a finish apparatus, 
 wherein, when the color sample is selected as a paper type of sheets housed in a sheet feeding tray of the sheet feeder, the processor makes a display a warning to use the PI tray. 
 
     
     
       10. The image forming apparatus of  claim 9 , wherein, when the color sample is set as a paper type of sheets housed in a sheet feeding tray of the sheet feeder, the processor stops receiving an image forming job and only carries out a passing operation of the color sample. 
     
     
       11. An image forming method of an image forming apparatus comprising a sheet feeder which houses and feeds a sheet, a sheet conveyor which conveys the sheet fed from the sheet feeder, an image former which forms an image on the sheet, a fixer which fixes the image formed on the sheet by the image former, a processor controlling at least one of the sheet conveyor, the image former and the fixer according to a condition for controlling deterioration of a color sample housed in the sheet feeder, and a colorimeter which is provided on a down-stream side of the fixer in a conveying direction and which reads the image formed on the sheet, the method comprising:
 calibrating the colorimeter based on an image for calibration read by the colorimeter, 
 wherein in the calibrating, when the colorimeter reads the image for calibration, which is formed in advance on the color sample, at least one of the sheet conveyor, the image former and the fixer is controlled according to a condition for controlling deterioration of the color sample which is different from a condition for carrying out an image forming process; 
 wherein, when the processor makes the sheet conveyor convey the color sample, the processor makes a pair of rollers of the fixer separate from each other and makes the color sample pass through the pair of rollers; 
 wherein, the processor determines whether a sheet length of the color sample in the sheet conveyance direction is longer or equal to a predetermined sheet length, which allows the color sample to be in contact with a conveying roller in front of the fixer and a conveying roller behind the fixer, and 
 wherein, when the processor determines that the sheet length of the color sample is longer or equal to the predetermined sheet length, the processor makes the sheet conveyor convey the color sample, and wherein when the processor determines that the sheet length of the color sample is less than the predetermined sheet length, the processor displays a warning to use a sheet whose length is longer or equal to the predetermined sheet length. 
 
     
     
       12. A non-transitory computer readable medium having a program stored thereon for controlling a computer of an image forming apparatus comprising a sheet feeder which houses and feeds a sheet, a sheet conveyor which conveys the sheet fed from the sheet feeder, an image former which forms an image on the sheet, a fixer which fixes the image formed on the sheet by the image former, and a colorimeter which is provided on a down-stream side of the fixer in a conveying direction and which reads the image formed on the sheet, the program, when being executed by a processor of the computer of the image forming apparatus, causing the processor to perform a process comprising:
 calibrating the colorimeter based on an image for calibration read by the colorimeter, and 
 when the colorimeter reads the image for calibration, which is formed in advance on a color sample, controlling at least one of the sheet conveyor, the image former and the fixer according to a condition for controlling deterioration of the color sample which is different from a condition for carrying out an image forming process; 
 wherein, when the processor makes the sheet conveyor convey the color sample, the processor makes a pair of rollers of the fixer separate from each other and makes the color sample pass through the pair of rollers; 
 wherein, the processor determines whether a sheet length of the color sample in the sheet conveyance direction is longer or equal to a predetermined sheet length, which allows the color sample to be in contact with a conveying roller in front of the fixer and a conveying roller behind the fixer, and 
 wherein, when the processor determines that the sheet length of the color sample is longer or equal to the predetermined sheet length, the processor makes the sheet conveyor convey the color sample, and wherein when the processor determines that the sheet length of the color sample is less than the predetermined sheet length, the processor displays a warning to use a sheet whose length is longer or equal to the predetermined sheet length.